In a previous posts we have stated our newly purchase 1960 MK2 was originally a 2.4L with a 3HA 4.55 rear axle. We have been advised that the ring/pinion cannot be replaced for a lower ratio. Our car now has a 3.8L engine with 4SP with OD, but retains the 4.55. So its really pretty quick, but not practical on the highway.

So we are looking for a 4HA complete axle to swap out with the 3HA. So if I can find one is it a direct swap?

What changes if any will be needed? Is the driveshaft need to be modified? etc etc.

So I am looking looking for a replacement if I can swap them. I understand a 3.77 is impossible to find. How about drivability of a 3.55??

Thanks

jjsandsms

 

I think a 3.4 engine would be quite OK driving a 3.55 diff.
My 1960 Mk2 2.4 manual overdrive with a full synchro gearbox was modified to a 3.77 diff by some previous owner and it handles the higher diff ratio quite happily.
It should be a direct swap as far as mounting the diff. but I can't comment on the tail shaft.

 

Bill,

S Type:
Axle ratio 3.54:1 with non-overdrive manual and automatic gearboxes ~ 3.77:1 with overdrive.

I see no issues with a 3.8 engine. Slight RPM/max speed change OD = 0.77 to 1 ~ Thirst for mpg?

 

I found this by searching more, so it appears the driveshaft must be shortened or source a manual with OD 3.4, 3.8 driveshaft
By the way my vin is 125457, so we just missed the changeover to the 4HA. Oh well, anyone got a later driveshaft?
Thanks
jjsandsms

 

So sorry for the junk, I tried to insert an photo....

jjsandsms

 

 

Just have the driveshaft shortened, trued & re-balanced. It is an easy job for a driveshaft shop.

 

I am still getting more confused with regard to 3HA v. 4HA - What's the difference? Since it seems that after Jaguar stated using the 4HA jus a few vehicles after mine, they still offered a 4.55 in the 2.4L ?

Are they both DANA44's ? In an earlier post I was advised that there is no way just to change the ring/pinion in my car, that I have to change the entire axle. what is the limiting issue? Nobody makes a lower ratio ring/pinion for the car!!

If we go with a 4HA with a 3.54 ratio then it seems if I could find a 3.77 the ring and pinion could be swapped in the 4HA's? But apparently not in the 3HA.

Sorry for my ignorance but this is so confusing and I do not wan to spend more money than necessary to get the proper drivability. I actually love driving the car as is as long as I don't have to get on the freeway!

With the current setup to go 63MPH requires about 3000rpm in overdrive, to go 70mph would be almost 3400rpm- a bit much.

If we swap axles to a 3.55 to go 70mph would only be about 2600rpm--quite a drop

A 3.77 at 70mph 2750rpm!

Thanks
jjsandsms

 

Update,

I can barely see a stamping number on the diff casing by squeezin under the car- and it appears to read 4HA004 - so do I have a 4HA carrier even though according to the manual service update it should have a 3HA. How externally can I verify?? Have verified it is a 4.55 ratio.

Thanks
jjsandsms

 

Take the back cover of (with a new gasket to hand) and count the number of teeth on the pinion & the crownwheel.

EDIT: or clean things up enough even if you have to resort to fine grit sandpaper to enjoy legibility of the number stamped/cast. Find a depression in the curb and put 2 wheels up on the curb to prevent you having to squeeze under the vehicle.

 

I have already convinced myself it is a 4.55 ratio as matching the actual speed v. rpm and then plugging into a calculator and the numbers verify, plus the tag, which of course cold not be correct. Yes we will take off the the cover at some point.

The 4HA004 is a casting protrusion hidden on the left side of the housing an almost impossible to find and harder to read as it is near the top. I tried photos but I only see the HA004 clearly. I did clay impression and it sure looks like a 4, its certainly not a 3.

But more to my point, if it is indeed an actual 4HA, if I ever find a 3.77 ring and pinion, can we remove the 4.55 and install the 3.77? I did a similar job on a Healey 3000 a few years ago and it is not east, but may easier and cheaper than buying an entire axle with a 3.54 which seems to be the only ones available.

Other mystery to me is what is the 4HA doing in a car that is suppose to be a 3HA and I still do not understand the different between the two, Splines, carrier dimensions ????

Are the housings serialized and if so where are they marked, I see nothing other than the heretofore hidden protrusion?

Again sorry for the numerous questions, but if we are going to make a change I want to ensure I buy only what is needed Once!

Thanks
jjsandsms

 

My 1967 MK2 2.4 has 4HA004 on the diff casing, you can just see it below and its a 4HA axle so if yours is the same I would suggest its a good bet that its a 4HA already.

Changing the diff gears is fairly straighforward but you do need some specilaist tools (pullers, DTI gauge etc.), also if you use a secondhand ring gear and pinion you have to be aware that its unlikely that you will get a perfect pattern on both drive and coast (when the engine is pushing the car and the car is pushing the engine).

There are lots of videos on-line about setting up a diff and worth watching if you want to give it a go as the process across most axles is basically the same.

If I remember correctly the 4.55:1 was for the manual overdrive 2.4 cars where as the non overdrive manual cars and auto (like mine is) are 4.27:1.

If you're not confident though get a specialist to do it, also be aware that removing the drive shafts on these cars can be a nightmare (more getting the hubs off the shafts to pull them out), some people get them off with a standard puller but they are in the minority and it might be that you need to hire the specialist puller and if you use it then leave the nut on the end of the shaft just backed off as they go with a hell of a lot force when they do move!

 

Also to add that when you but a crownwheel and pinion gear set, if its an original one it will have the required backlash engraved on the crown wheel as the picture of mine below, I read about it and the general concensus was that it should not be less that 4thou, mine was 4.7 thou in the end and it seems fine in use, remember the because the teeth on the gear aren't square moving a shim from one side of the diff to the other doesn't have a directly proportional effect on the backlash. It was about 13.5 thou when I took it appart and the car had done around 77K miles from new (was only one the road for 10 years).



Also you need a special case spreading tool to get the diff out, here is mine, only the finest quality tools in my workshop

 

Yep! Your diff seems to have the number 4HA004 in the same place as mine. See my photo. Interesting (and good news to me) then that I have the 4HA when in fact car should not. But who knows what prior owners did to the car over the 63 years!. I suspect the diff is original and the car was so close to the factory making the switch in Vin numbers that it made the cut.
The fact the case has to be spread apart is something else. I hope you had all kinds of protective bullet proof vest and safety glasses on.....

Now if I can just find a 3.77 to replace the 4.55. I have located an entire axle with a 3.54 in it but it is very costly with the shipping. Seems like replacing the entire unit would be a bit easier since it has to come out anyway,

But I really dont want a 3.55 unless you all can say it is the way to go with a 3.8L 4 speed OD.

Thanks so much.

jjsandsms

 

Homer is spot on. All that is required is a little patience & the correct tools. I set up my pinion preload and was fastidious with tooth alignment on my S Type & I have a dead silent axle (both acceleration & overun) and the axle has 90,000 miles on it. Of course it has new bearings etc. but original crownwheel & pinion.

 

Did you find a 3.77 (49/13) Crown & Pinion for your Salisbury? I have a Salisbury 4HA with a 3.77 that I'm changing out to a 3.31 using the Yukon Dana 44 kit. I'd be interested in selling you the 3.77 C&P, or possibly trading for your 3.54. Although I'd prefer 3.31 gearing, 3.54 would be close enough to what I want and the swap would be easier for me than the Dana 44 kit. Let me know asap, as I'm disassembling the 4HA starting today. Thanks!

 

Thanks for the reply. I did find an entire 3.77 power lock 4ha axle. I have performed the swap and all seems ok.
So I have the original 4.55 Salisbury 4ha axle complete with new brake disks. The C&P have perfect wear pattern and the entire unit is rust free. So I am looking to sell the entire unit.

Thanks
Jjsandsms

 

Thanks for the quick reply! Congrats on the successful swap. Unfortunately, I can't use the 4.55 C&P as I want higher gearing (lower #) from the 3.77 I have now. So, I guess I'll stick with my plan to do the D44-331 C&P swap. Thanks again!

 

Jagjonz having read this thread for my understanding of this type of project and I believe I may be interested in buying your 3:77 C&P I just need to confirm firstly that it will fit my Daimler V8 to convert it from a 4:55 ratio to allow lower rev cruising. Can you please let me know if you still have it and how exchanges etc etc are arranged on this forum. 🤞🤞🤞

 

Doherto, Yes, I still have the 3.77 CWP for a Salisbury 2HA. It should fit your Daimler if you have a 2HA rear diff. It won't fit a 3 or 4HA.